This invention relates to methods of forming integrated circuitry memory devices, to methods of forming dynamic random access memory (DRAM) device arrays, and to semiconductor masks.
Processing of semiconductor devices typically involves many steps in which layers of material are formed over a substrate and subsequently patterned into a desired feature or structure. Typical features or structures include conductive lines and contact openings. Each time a patterning or etching step is conducted, certain risks arise which can jeopardize the integrity of a wafer being processed. For example, a mask misalignment error can cause a subsequent etch to undesirably etch into wafer or substrate structure which can cause catastrophic failure. Accordingly, a need exists to reduce the number of processing steps utilized in the formation of integrated circuitry.
This invention arose out of concerns associated with reducing the number of processing steps needed in the formation of integrated circuitry. This invention also arose out of concerns associated with improving the manner in which integrated circuitry memory devices, and in particular DRAM devices are fabricated.
Methods of forming integrated circuitry memory devices are described. In a preferred implementation, methods of forming DRAM arrays are described. According to one aspect of the invention, a plurality of continuous active areas are formed relative to a semiconductive substrate. A plurality of word lines and active area isolation lines are formed over the continuous active areas. An insulative layer is formed over the word lines and active area isolation lines and in a common masking step, both capacitor contact openings and bit line contact openings are patterned over the insulative layer. Subsequently, capacitor contact openings and bit line contact openings are etched through the insulative layer over the continuous active area. In a preferred implementation, the capacitor contact openings and the bit line contact openings are contemporaneously patterned and etched. Subsequently, conductive material is formed within the openings to provide conductive plugs. Capacitors and bit lines are then formed to be in electrical communication with the respective conductive plugs within the respective capacitor contact openings or bit line contact openings.